An annual rally calling on Moscow to return the islands it seized off Hokkaido at the end of World War II was held Tuesday in Tokyo with government officials, lawmakers and former islanders in attendance.
Russia has hardened its stance on the long-standing territorial dispute that has prevented Tokyo and Moscow from signing a peace treaty.
Soviet forces seized the islands of Etorofu, Kunashiri and Shikotan and the Habomai islets near the end of the war. Japan has said some 17,000 islanders fled or were forced out in the occupation.
To the disappointment of participants in Tuesday's rally, Prime Minister Junichiro Koizumi skipped the event and sent no representative.
It was the first time a prime minister has refrained from attending the rally or sending someone to give an address.
Among the Cabinet ministers who attended the gathering, Foreign Minister Taro Aso voiced concern for the aging former islanders.